Electro-magnet



's No Model/n G. D. CLARKE. ELECTRO MAGNET.

Patented Apr. 1,1890.

and more particularly to the winding of the UNITED STATES PATE-NT Orricri.

' GEORGE D. CLARKE, OF CHICAGO, ILLINOIS.

ELECTRO-MAGNET.

SPECIFICATION forming part of4 Letters Patent No. 424,703, dated April 1, 1890. Application filed March 30, 1889E Serial No. 305.461. (No model.)

To all whom it may concern:

Be it known that L'GEORGE D. CLARKE, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Electro-Magnets, which is fully set forth in the following specification, reference being had to the accompanying drawings, in whichl Figure 1 is an elevation, partly in section, of a construction embodying my invention; Fig. 2, a plan section of the same, taken on the line 1 1 of Fig. 1; Fig. 3, a View similar to Fig. 1, illustrating a modified form of my invention; Fig. 4, a plan section of the same, taken on the line 2 2 of Fig. 3; Fig. 5,a View similar to Fig. l, illustrating a second modi cation of my invention; Fig. 6, -a sectional view of the same, taken on the line 3 3 of Fig.- 5; Fig. 7, a View similar` to Fig. l, illus- -trating a third modification; and Fig. 8, a

sectional view taken on the line 4 4 of Fig. 7.

Like letters refer to like parts in all the figlures of the drawings.

My invention relates to electro-magnets,

same, or, in other words, to that portion commonly known as the spool. In such spools as generally constructed the essential ele ments are a core, a disk or head near each end of the core, and a wrapping or coil of coutinuous wire wound around the core, so as to occupy the space between the disks or heads. This wire of course presents two ends, the inner one of which is immediately adjacent to the core and the outer one on the outer surface of the coil, and these ends are passed through one of the disks or heads, which is provided with suitable perforations for this purpose, the said ends projecting sufficiently to permit of their being readily connected to other wires, as desired. These projecting ends frequently break off at the point where they leave the disk or head, owing to their being frequently bent in different directions at these points. If the outside end breaks, it is a comparatively simple matter to unwind one turn of thewire `from the exterior of the coil and passv the slack thus obtained through the aperture in the disk, thus obtaining a new eild butfif the inside end breaks it will be at once seen that this course cannot be pursued, owing to the inaccessibility of the inner turns, and it has heretofore been necessary in such cases to entirely unwind and rewind the spool in order to obtain a new end with sufficient slack to make the necessary connections. I

The object of my present invention is to obviate this difficulty and prevent the neces- 6o sity of nnwinding and rewiuding the spool; and to these ends my invention consists in certain novel features, which I will now proceed to describe, and will then particularly point out in the claim.

In Figs. 'l and 2 of the drawings I have shown a construction in which myinvention is embodied in its preferred form. In this construction A represents t-he core, and B the end disks or heads, these latter being con- 7o strueted of hard rubber or other suitable insulating material. C represents the insulated wire, which is coiled around 'the core A, between the disks or heads B, its outer end being represented at c and shown as passing 7.5 through a perforation Z1, formed through one of the heads ordisks B, near its margin, in the usual manner. v Z2 indicates a second perforation, formed through the disk B at a point immediately adjacent to the core A, and 8o through which in the ordinary construction the inner end c of the wire C would be passed. B represents a circumferential groove formed in the head B of a suliicient depth to communicate with the perforation b. W'ithin 85 this groove there is coiled a wire D, the inner end of which is connected t0 the inner end c of the wire C, while its outer end is passed through a perforation b2, formed through the head B, near the outer margin thereof, this 9o projecting end (Z serving as a means of connection in the same manner as the projecting end c. Now, it will be seen that if the projecting end CZ breaks olf at the point where it issues from the head B it is only necessary to unwrap the outer turn of the wire D,which is coiled within the groove B', and thus ob` tain suliicient slack to form a new end, which is passed through the aperture b2 and will to any desired wire or other object.

In Figs. 3 and 4 of the drawingsl have project suiiiciently to admit of its connection rook shown a modified form of my invention, in

' which D' represents a ring or annulus con- -1 and 2.

structed of some suitable conducting-material-such as brass-and provided with inf wardly-proj ecting lugs df, which may be bent lwhich extends 4outward beyond the head of the spool and has connected to it a wire d3, which takes the place of the ordinary projecting inside end in the same manner as does the wire d in the constructionshown in Figs. rlhis connection being an external one, it will be at once seen that any break at this'V point may be readily repaired without -nnwindin g and rewindin g the spool. In pracvtice a layer of paraiiine paper or other suitable insulating material will be interposed vbetween the ring D and the coil, in order to more thoroughly insulate the two.

In the construction shown in Figs. 5 and 6 I have shown a modicationin which the head B is provided with an aperture b3 and a groove b4, extending radially outward therefrom, in which groove is. seated and retained a strip D2, of suitable conducting material-such as brass or the like-to the inner end of which the inner end c of the wire G is connected, while to its outer projecting end the Wi re d3 is connected.

In the construction shown in Figs. 7 and S, which illustrates a further modiication, a small hole is bored inward t rom the outer edge of the head B into the aperture b3, and a short g rod D3 s inserted through this hole, its inner i end projecting into the aperture b3, where the inner end c of the wire C is secured to it,

while. its outer end projects beynd the head B and has secured to it the wire d3.

It will be observed that in each of the constructions described the head of the spool is provided with an intermediate connectingpiece of conducting material, to one end of which the inner end of the coil of wire is connected, while its other end provides a means for the connection of the coil to the line of wire or other object to which it isdesired to connect it. In the form shown in Fig. 1 this intermediate connecting-piece may be in one piece with the coil of wire, if desired. It will also be observed that in case of the breaking of the wire at the point where it leaves the spool the break may be readily repaired without the necessity of unwinding and row-inding the spool.

It is obvious that various modifications in the details of cnstruction may be made without departing from the principle of my invention, and I therefore do not wish to be understood as limiting myself strictly to the precise details hereinbefore described and shown in the drawings.

`Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

The combination, with the coil C, having outer end c and inner end c', of the spool composed of the core A and heads B, one of said heads being provided with suitable apertures for the ends of the coil and having a circumferential groove B', and the wire D, coiled in said groove and having its inner end connected to the inner end c of the coil C and its outer end led through one of the apertures in the head, substantially as and for the purposes specified.

GEORGE D. CLARKE.

Vitnesses:

A. M. BEST, IRVINE MILLER. 

